1. Field of the Invention
The present invention relates to a tie-down assembly for tightening down and tensioning a strap for tying down and securing loads, and more particularly to a tie-down assembly that includes a tensioning device that uses ratchet means to wind up and secure a tensioning strap in a tensioned condition.
2. Description of the Related Art
Ratchet-type strap tensioning devices are well known for winding up tensioning straps and securing the straps in a tensioned condition to secure loads for hauling or transport. An example of such a device is disclosed in U.S. Pat. No. 4,185,360 to Prete, Jr. et al. and generally consists of a frame or base member and a lever arm which is moved relative to the frame that drives a ratchet mechanism that rotates a slotted reel through which the tensioning strap is thread, advancing the strap into a tensioned condition. Typical ratchet-type strap tensioning devices have one end of the frame secured in a fixed relationship to an anchor point, for example, by means of short piece of strap attached at one end of the frame with the other end fixed to a hook that is secured to the anchor point. A second hook fixed to a longer length of tensioning strap is then secured to a second anchor point and the strap is threaded through a slotted reel on the tensioning device. Rotation of the reel by means of the ratchet mechanism winds the strap into a tensioned condition and secures the load. A disadvantage of such a configuration is that the device cannot be relocated or repositioned along the length of the tensioning strap to facilitate easier operation of the device, as would be desirable for instance where the position of the anchor points results in awkward or confined spaces for ratcheting the device. Another disadvantage is that the device cannot be repositioned to better conform the device to the configuration of the secured load prior to tensioning the strap, as would be desirable, for example, when the configuration of the secured load presents a fragile or a non-planar surface near the anchor points that would lead to damage to the load were the tensioning device tightened down a that location.
Attempts have been made to provide a strap tensioning device that provides for movement of the device along the tensioning strap. U.S. Pat. No. 3,826,473 to Huber, discloses such a device. This device consists of a single frame structure that includes a reel for winding up a tension strap where the reel is driven by means of a torque wrench.
It would be advantageous to provide a tensioning device that is easily moveable along a tensioning strap and that also provides for ease of operation. Ideally, such a device will be of a configuration that provides for a minimum of wear on the tensioning strap during adjustment of the device along the strap prior to winding up the strap into a tensioned condition and that also ensures good control of the device during the winding up operation.